Inheritance of the Low-Phytate Trait in Pea
Field pea (Pisum sativum L.) is the most widely grown pulse crop in Canada and has total seed P concentration greater than 3 mg g−1. However, about 60 to 80% of the total P is stored as phytate, an organic molecule that binds with some mineral cations and is excreted due to the lack of phytase enzymes in humans and non-ruminant animals. This causes nutrient deficiency as well as environmental pollution. The objective of this research was to determine the genetic control of the low-phytate trait in two recently developed pea lines: 1-150-81 and 1-2347-144. Both lines and two normal-phytate cultivars were used in crosses to develop five populations, including one reciprocal. The F1 seeds from the five crosses all had normal phytate concentration, indicating recessive inheritance. The F2 segregation ratios for the five crosses fit a phenotypic ratio of 3 normal:1 low phytate. The F2 individuals from 12 backcross populations fit a ratio of 3:1 with the exception of one population (1-150-81/CDC Meadow//CDC Meadow). The segregation of 1057 F2:4 lines from the six single cross-derived populations were tested and five of six populations fit a ratio of 1:2:1 homogeneous normal phytate:segregating:homogeneous low phytate. Taken together, these data support a single gene model with the low-phytate phenotype being recessive. The two low-phytate lines were intercrossed and the F2 seeds all displayed the low-phytate phenotype indicating that the mutated genes were allelic.
Rehman, A.U.; Shunmugam, A.; Arganosa, G.; Bett, K.E.; Warkentin, T.D. Inheritance of the Low-Phytate Trait in Pea. Crop Science (2012) 52 (3) 1171-1175. [DOI: 10.2135/cropsci2011.08.0432]